Online Calculator

Voltage Drop Calculator

K-factor circular-mil math with the 3%/5% NEC guidelines applied.

Voltage drop

4.44 V (3.7%)

Voltage at load
115.56 V
Verdict
Acceptable only if total ≤5%

How the Voltage Drop Calculator works

The calculation follows the standard method used across the US — no shortcuts, no hidden assumptions. Here is exactly what happens behind the scenes:

Frequently Asked Questions

How does the Voltage Drop Calculator work?

Enter your numbers above and results update instantly using standard formulas, computed entirely on your device.

Is the Voltage Drop Calculator free to use?

Yes — completely free with no signup required, and it works on phones, tablets, and desktops.